Transmission



Patented Aug. 20, 1946 Donald W. Kelbel, Muncie, Ind., assigner to BorglWarner Corporation, Chicago, Ill., a corporation of Illinois ApplicationAugust 3, 1944, .Serial No. 547,819

2 Claims. (01.74-27 0) My vinvention relates to power transmissions,

and more particularly to transmissions suitable for use in automotivevehicles. i y Y It is an object of lmy-invention to provide an improvedtransmission which is of such construction that a suitable number ofspeed ratios for driving an automotive vehicle may be obtained with aminimum amount of gearing.

It'is another object of my invention to provide an improved transmissionwhich may be easily controlled for changing the speed ratio through thetransmission.

It is a further object of my invention to provide an improvedtransmission having low and intermediate speed ratios in which, at thewill of the operator, the driven shaft may either freewheel with respectto the drive shaft or in which the two shafts may .be positivelyconnected. It is contemplated that the transmission shall preferablyprovide a direct drive ratio positively connecting the drive and drivenshafts.

It is still another object ofthe invention to provide such atransmission which may be easily controlled so that the driven shaft maydrive the drive shaft at one of the lower speed ratios of thetransmission for starting an internal combustion driving engineconnected with the drive shaft.

The invention consists of the novel constructions, arrangements anddevices to be hereinafter described and claimed for carrying out theabove stated objects and such other objects as will appear from thefollowing description of certain preferred embodiments illustrated inthe accompanying drawings, wherein:

Fig. 1 is a longitudinal sectional View of a transmission embodying `theprinciples of the invention;

Fig. 2 is a sectional View taken on line 2-2 of rig. 1; e

Fig. 3 is a diagrammatic illustration of the transmission shown in Fig.l;

Fig. 4 is a diagrammatic illustration of another embodiment of theinvention; and

Fig. 5 is a diagrammatic illustration of a third embodiment of theinvention.

Like characters of reference designate like parts in the several views.

Referring now to Figs. 1 to 3, and in particular to Fig. 3, thetransmission illustrated therein comprises briefly, a drive shaft I0, adriven shaft I2, a planetary gear set I4 connected to drive the shaftl2, a centrifugal clutch I6 for connecting the drive shaft I0 with theplanetary gear set by means of an intermediate shaft I8,

and another clutch 20 for connecting the drive shaft vIl) with theplanetary gearing by means of another intermediate shaft 22. Theplanetary gear set I4 comprises a reaction element 24 which whenl `heldstationary functions to complete a power train through the planetarygear set between the shafts I0 and I2 when either of the brake 26 isprovided for the reaction element 24,

and ablocker 28 allows engagement of the brake,

26 only when the reaction element is rotating in a 4direction reverse`with respect to the direction of rotation of the shaft I0. A holdingmechanism 30, adapted to be selectively operated, is provided Vforholding the brake 26 engaged, and a clutch 32 4comprising cammedinterengaging teeth `is disposed between the reaction element 24andanother element of the planetary gearing I4 to lock the elementstogether and to lock up the gearing for the purposeswhich will behereinafter described. The reaction element 24 is movablellongitudinally with respect to the shaft I2 either by means of a collar34 on the reaction element or by means of spiral gearing 36 which isapart of the planetary gear set I4 in order to either engage the brake26 or the clutch 32. A positive typevbrake 38. is provided for the shaft22 and the planetary gearing for providing a reverse 'drive through thetransmissionV as will be hereinafter described.

Referring now in particular to Figs. l and 2 for amore detailedYdescription of the transmission, vit will be observed that thetwo-clutches I6 and 20 are positioned closely together and form parts-ofa single clutch assembly. This assembly comprises a. fly-wheel 4l) fixedto the shaft .44 V,comprising annular sheet metal parts 46 and 48 Vandalso a piston ring 50, held by a retainer .ring '52 with respect to theparts 46 and'48, is

provided within the cover plate 42. The piston 44 isdisposed between aYcylindrical portion 54 formed in thecover plate 42 and a sleeve 56disposed on.. the shaft 22 and fixed with respect to thecover plate 42.A fluid conduit 58 passing through the shafts I8 and 22 and the sleeve56 is provided to Asupply fluid from any .suitable source to the rear ofthe piston 44, and between the piston and the cover plate 42 to forcethe annular sheet metal member 60. disposed about the -member 46. Themember 60 has a plurality of lug portions 62 each' of whichpassesth'rough a slot 64 provided in the side of the fly-Wheel 4|),`

means of screws l2, a pressure plate 'i4 formed,` by sheet metal membersi6` and 7S. A plurality of springs Si? are provided in suitable cavitiesin the side of the fly-wheel 40 'and act 0n the member 66 for yieldablyholding the members 66, 66 and the piston 44 at therearward limit ofmovement of these parts with the member 48 of thepiston bearing againstthe cover plate 42 as shown. Each of the slots E4 has a bottom 82 whichfunctions` to limit the movement of the member SQ toward the front ofthe clutch as sembly, and each of theslots lil is providedwith a bottom84| whichr functions to limit, the movement in the same direction' orthe sheet jmetal member 63. The parts of the clutch assembly so fardescribed function so that, when iiuid under pressure is admittedbehind'the piston 44, the piston, the parts 60 and E5 and the pressureplate 74 are moved forward until the lugs |52 Contact the bottoms 82 ofthe slots $4,

The clutch l5, after uid under pressure has been applied to the piston44 to move the lug portions E2 ofthe member 6|] linto Contact with thebottoms 'S2 of the Vslots 64, is conditioned to be engaged according tothe speed of the shaft ii). VCentrifugal weights 86 perform thisfunction ,ofY centrifugally engaging the clutch. The

Y member Se is provided with outwardly extend- 4ing wing or lug portions88 and each of these portions is provided with a notch 99 in which isreceived an acute portion 92 o f a weight 86, ythe arrangement beingsuch that the notch 'Sacts as a fulcrum for the) weight, allowing theweight to move outwardly under the influence of centrifugal force due torotation of the shaft I0, the

`fly-wheel 4e, the member B and thereby the `movement of. the weights85, and as will be apparent, such movement of the pressure plate 14 isalso similarly opposed by the springs 80. Y The clutch itV comprises, inaddition to theV fly-wheel Yit and the pressure plate 14, the drivenplate |66 which is connected by means of a vibration absorbing unit |62of any suitable construction withV a hub HB4 which is'splined to theshaft I8. The Weights 85 function, afterv fluid under pressurehas beenappliedto the piston 44 to move'the piston and the associated parts sothat the member E3 contacts' the bottoms 82 ofthe slots B4lforconditioning the clutch l5, for engagement,

tofmove the pressureplate 14 the additional distance needed to engagethe clutchrl.

. A pistoni |36 is provided for engaging the clutch 2t, `'Ik'hispistoncomprises a memberl lilof` Vsheet metaL' a piston ring [l0 of vayielding'material,

4 and a sheet` metal retainer member ||2`. member H2 holds the ring ||i|in placewith respect to the member |48, and it has a perforated flangeH4 functioning to space the members |08 and 48. The piston |66 isdisposed between and is movable with respect to a cylindrical portion H6of the member 46 and the sleeve. A fluid conduit H8 extending throughthe sleeve 56 and the shafts H3 and 22 is provided for Vsupplying uidunder pressure from any suitable source to the rear of the piston l. Apressure plate movable bythe piston iil is formed by the member |S8 andan annular member |22J as shown.

The sleeve 56 has an 'annular member |24 fixed thereon against forwardmovement, and springs |26 and |28 are provided between the member .Idiland the member |24. These springs function to yieldingly oppose movementof the piston |66 forwardly, and the springs, together with the springs613, function also to oppose forward movement of the piston 44 and its`associated parts. The clutch 2S comprises, in addition to the pressureplate 'i4 and the pressure Vplate |20, adriven Vclutch disc i3d. Thedisc |3||`has a hub |32 that is splined to the shaft 22 Yso as to benon-rotatable with respect to the shaft butthe hub may have longitudinalmovement on the shaft. The

clutch 26 is engaged by applying fluid under 'presby means of a bearing|36, and the Vshaft It is also piloted in the driven shaft I2, as shown.The shaft Yi8 has a sun ,gear |38 formed thereon, andthe shaft r22 isprovidedwith a ringjgear |40, both of the gears |88 and |41), formingp-@Its'of `the planet gear set i4.Y rhe gear set i4 ,comprises` alsoplanety gears |42 wliich'are in meshjwiththe sun gear |35 and planetgears- |44 which are in mesh with the planet gears |42 and with the ringgear Mt. A spiral planet gear |43 is integrally.

connected with each of the gears |44, andthe spiral gears are in meshwith a spiral sun gear |48 formed on the reaction element 24. The gears|455 and |46 together fQlmthespiral'gearing B'hereinbefore referred to,and the reaction element 24 is Vrotatably and longitudinallymovablydisposed on the driven shaft i2. The planet, gears |42, |44 and it@ arerotatably disposed on a carrier |5@ which is connected withtheshaft Thering gear |46 is provided with'teeth |52 on its outer periphery, and apawl |54 carried by the transmission casing |34 is provided for engagingwith the teeth M2. Y The,pawljl54 and the teeth |52 together form thepositive brakeBS for the ring gear |43 and the sliaftZZ.v l Y .ThePlanetary gear set issuch thatrwhen the reaction element 24, along withits' sun gear |48, is held stationary and the shaft LS and its sun gear|38 are driven through the clutch'JiS, the carrier |56 and the drivenshaft l2 connected therewith are driven at a low ratio forward drive.When the ring gear |45 is driven'through the clutch, and the reactionelement 24 is held stationary, with the clutch la beingY disengaged,thev oarrierji` 5|! and the shaft|2 are driven atan intermediatespeedforward drive.) ,Whenbo'thof the clutches l and 2G are :engaged and thereac-KK The' sion. Inoted by the frictional retardation of rotation oftionv element 24 is' allowedto rotate freely,-the

vplanet gearing I4 is locked up and the 4carrier |50 and the drivenshaft I2 are driven at a one to `one ratio with respect totheintermediate shafts I8 and 22 and the drive shaft I0. When the brake 33is engaged to hold the ring gear |40 stationary and the clutch It isengaged and the reaction element 24 is released to rotate freely, thecarrier |50 and the shaft I2 are driven at a low speed in reverse drive.

The reaction element `2d: in its'movement may be controlled by a collar34, a toothed clutch 32, a positive type brake 26, a blocker Y28 and aretaining mechanism 3@ for holding the element from longitudinalmovement, all hereinbefore referred to. The collar 34 is splined on theelement 24 and is fixed against longitudinal movement on the element bysuitable retainer rings, as shown. The brake 20 comprises stationaryteeth |56 carried by the transmission casing 134 'and brake teeth |58formed on the reaction element 24 and adapted to mesh with the teeth|55. The blocker mechanism 23 comprises a blocker element |550 which isdisposed on and may have limited os cillatory movement with respect tothe element 24 and which is held in friotional engagement with astationary part |62, fixed with respect to the transmission casingI3Ll,.by means of a spring |63 between the collar 34 and the blo-ckerelement |50. The blocker mechanism maybe of any suit,-

lable construction and is such as to prevent rearward movement of theelement 24 and block engagement of the teeth |58 with the teeth |55 whenthe element is rotating' in a forward direction, that is, in the samedirection as the drive shaft |0, and the blocker mechanism allows suchmovement of the element 24 and engagement of the yteeth |53 with theteeth |55 when the rotation of the element 24 is in the oppositedirection. The brake 26 is engaged automatically to hold the reactionelement 24 stationary when either of the clutches |B and 20 is engagedto provide a reduced speed ratio through the transmission. The spiralgearing 35 functions to move the reaction element 24 longitudinally ofthe shaft I2 either in one direction or in the other depending on thedirection ofl reaction on the element 24 by the gearing. If the reactionon the element 24 is in the reverse direction, the spiral gearing urgesthe element longitudinally rearwardly of the transmission tending toengage the teeth |58 with the teeth |56, while if the reaction on theelement 24 is in Y 6 elements |64 4which are slidablydisposed in suit.-

-ab1e;cavities in the casing |34: and are'adaptedto :fitin a groove vI60 in the reaction element 24 .when

the teeth |58 are interengag'eklU with the teeth |503.A''sleeveflike'memberfl|58. is disposed about the4 elements V|64 andisprovided with cams |10 on its inner surface for acting on the elements|64. The member |68 is adapted to be operated i manually or by anysuitable means, and when the reaction element 24 is moved rearwardlyfrom its position as shown in Fig. 1 to engage the teeth |58 with theteeth |55, rot-ation of the member |20 will cause the cams |10 to lockthe bean elements |64 in the groove |06 and thus prevent any forwardmovement of the reaction element 24. When the transmission is either inlow or i intermediate speed,.with either of the clutches I0 and 20engaged, the spiral gearing 36 acting on the reaction element 24 tendsto cause the latter element .to be moved forwardly'of the transmissionto disengage the positive brake 20 when` the shaft i2 is allowed todrive, as when the power on the shaft Ii is decreased, and the'spiralgearing 3% together with the reaction element 24 and the brake 26 thusact as a free-wheel brake on lthe reaction element 24when the mechanism30 is disengaged. When the mechanism 30 is engaged, withthe'transmission being conditioned either for low or intermediateforward drive, the bean ele-ments |64 lprevent forward movement of thereaction element 24 and thus function to prevent this free-wheelingaction of the reaction element 24, and the shafts |0 and I2 are.positively connected through the gear set I4 in both speed ratios.

When the brake i-is engaged to condition the gear set I4. for reversedrive, the reaction on the element 24 is in a reverse direction whichtends the opposite or forward direction, the element 24 l is urgedlongitudinally forwardly of the transmis- Such action by the spiralgearing is prothe element 24 by thel blocker element |60 frictionallyAengaging with the stationary part |52. When either of the clutches `I 6and 20 is engaged, the reaction on the element 24 is in the reversedirection and the spiral gearing urges the element 24 rearwardly of thetransmission. On such rotation and longitudinal movement of the element24, the blocker mechanism 28 allows engagement "of the teeth |58 withthe teeth IE5, and the ele- The locking mechanism30 comprises bean-like75 to move the element 24 rearwardly of the transmission to engage thebrake 25. In this case, the collar 34 is utilized to hold the reactionelement\ against such rearward movement for preventing engagement of thebrake 25.

The clutch 32 comprises clutch teeth |12 on the carrier |50 and clutchteeth v|14 on the collar 34. The collar is splined to theV reactionelement 22, and the teeth |14 are thus xedwith respect to the reactionelement. The teeth |12 and |15 are slanted or beveled, as shown, and theclutch 32 may thus engage when the reaction element 24 rotates in aforward direction with respectto the carrier |50 but cannot engage ifthe relative direction of rotation of the element 24 is in the oppositedirection. The clutch 32 is utilized for locking up the planetary gearset|4 when it is desired to provide a connection between the shaft I2and the shaftV I0, with only the clutch 20 being engaged, as forstarting an `internal combustion engine (not shown) connected with theshaft I0 f by rotating the shaft I2. The clutch I6, in case the shaft I0is not in rotation, cannot be engaged, as will be readily understood,sincethis clutch is of the f centrifugal typeactuated by rotationof theshaft I0. When the clutch 20 is' engaged and the shaft I2 is rotated inthe forward direction, the reaction on the reaction element 24 is in` aforward direction and the spiral gearing 36 functions'to movethe'element 24 forwardly of the transmission. Such movement of thereaction element 24 causes engagement of the clutch 32 to lock up'thegear set I4 andxcomplete the connection from the shaft |2 to the shaft0. When the engine connected with the shaft I0 is started and begins `todrive, then the carrier I 50` tendsto .rotate faster in arforwarddirection than the ,K drive between the shafts I and I2.

reactioneiement 24 and the reactionbnitne eie-` ment 24 is .in thereverse direction, .andtheelement24 'is moved rearwardly ofthetransmission andthe clutch 32`is disengaged. y

.'.In' brief, the operation of the transmission illuvstrated in'Figs.1..to.3'is as followsz Whenit lis desired to .provide forward drive atlow ratio through the transmission, the clutch I is con-r ditioned for.operation `by applying fluid under pressure behind thepiston 44 to movethe piston and the associated parts including the'member 55 to bring thelugs 62 of the latter member, into engagement with the bottoms 82 of theslots .64.

. spiral gearing 35 will cause a reaction on the reaction element 24inthe reverse direction and l.

y will move r-itrearwardly of the transmission. .Such

movementof the reaction element 24 rwill disengage the blcckerrnechanism28 and will en- -n gage .the brake 2% to complete the low speed powertrain through the transmission. ToV shift the transmission tointermediate speed, the clutch l is disengaged by draining the fluidfrom behind the piston e4, and the clutch 2i! is engaged by ap-n plying'duid underpressure to the .piston IE6 and between the piston parts |98and 4E. Clutch 2d will then drive the planet gear set |4 through theshaft 22. The brake'Z will remain engaged, and the intermediate speed`power train through the transmission will. be completed. It will beunderstood that 'both of these power trains are of the free wheeling'type due to the free wheeling' action of the reaction element 24;however, both of the drives may be made positive by engaging themechanism 39,. as has been hereinbefore described. To shift thetransmission to direct drive, the clutch It is again engaged, with theclutch 29 remaining `engaged, by applying duid under pressurebehind thepiston 44. The planet gear set I4 will be locked upand there will be adirect The brake 2 5 for the element 24 will be disengaged due totheaction of the spiral gearing St, as has been Vhereinbefore described.For reverse drive, the

brake 38 is. engaged, and the reaction element 2:?

' is held against rearward longitudinal movement by useof the collar 34,and the clutch .l5 is engaged yto complete the low speed reverse drive.For causing rotation of the shaft i@ by rotating the shaft I2 as forstarting a driving enginethe second speed clutch 2E! is engaged, and theaction of the spiral gearing 36 will engage the clutch 312 to lock upthe planetary .gear set and complete a drive from the driven shaft I2 tothe drive shaft Referring to Fig. 4 of the drawings, themodicationtherein shown differs from-the construction shown in Figs. 1 to 3 inproviding a simpler positive type brake forthe reaction element and inproviding a somewhat different type of positive brake for the ring gear|40 of the planet gear setV I4. The brake for the reaction element 24 inthis embodiment 4of the invention comprises simply brake teeth`I'l41fixed with .respect to the reaction element and a pawl |16 whichis adapted to engage with the teeth '|14' to hold the 'teeth and thereaction elementV stationary. 'The brake rfor the ring gear |4|I 'foruse in reverse comprises y a'sleeve I'I8`splinedto :theshaft 22 andhaving teeth |89 eng-ageablewith.stationary teeth, |82.V The brake Yforthe shaft 22 may be engaged simply by moving .the sleeve |18 to ,engagetheteeth with the teeth |82. This embodiment of the invention operatessimilarly to the embodiment first .described with the exception that thebrake for the reaction element 24 is engaged and disengaged manually.

Referring to Fig. 5 of thedrawings, the embodimentof the invention shownin this figure isquite similar to that shown in Figs. 1 to 3 diieringonly from the latter embodiment inV having a different'brake structurefor the reaction element 24. The brake structure for the reactionelement 24 in this embodiment'comprises Va one-way roller brake unit |64which is con-Y nected in series with and is made effective by a positivetype brakecomprising teeth |36 yand a rotationally fixed pawl '|88adapted to engage with the teeth. A friction brakeV |90 is provided forthe reaction element 24 and is disposed in parallel with the one-waybrake structure. This embodiment operates quite similarly toltheembodiment shown in Figs. l to 3 with the one-way brake unit |34operatingsimilarly to the spiral gearing 36 and the positive'brake 26acting on the reaction element 24. The friction brake 98 functions quitesimilarly to the locking mechanism 3i) in the first embodiment of theinvention and may be Vapplied to provide a positivedrive in either lowor intermediate speed bctween'the drive and driven shafts.

I wish it to be understood that my invention is not to be limited tothespecific constructions and arrangements shown .and described except onlyinsofar as the claims may be so limited, as it will be apparent to thoseskilled in the art that changes may be made without departing from theprinciples of the invention.

IV claim:

l. In a transmissionthe combination of a drive shaft, a driven shaft, aplanetary .gear'set connected to drive said driven shaft and including asun gear, a ring gearl a first planet gear in .mesh with said sun gear,a second planet .geargin mesh with said first planet gearfand with Vsaidring gear a third'planet gear integrally connected withfone of saidfirst two named planet gears, and. a sun `gear constituting a reactiongear vand in mesh with saidr third planet gear, a clutch for connectingsaid drive shaft with said first Anamed sun gear to provide a powertrain between said vshafts at a certain speed'ratio, a clutch forconnecting said drive shaft with said ring gear to Y.

provide a power train between said shafts at another speed ratio, andmeans for braking said reaction gear to provide a reaction point forVthe j gear set to complete both of said power trains, saidv brakingvmeans comprising a one-Way roller brake the inner race of which isformed on a hub of said `reaction sun gear and the outer race of whichhas external teeth, anon-rotatable pawl adapted to engage the teeth ofsaid outer roller race to prevent rotation thereof and to thereby renderthe one-way brake effective, a brake drum connected to the hub of saidreaction .sun gear, and selectively operable friction means for stoppingthe rotation of said drum and for thereby braking the reaction sun gearin both ydirections of rotation.

2. In a transmission, the combinationV of a drive shaft, a driven shaft,asplanetary gear set connected to drive said driven shaft and includingasun gear, a ring gear, a first planet gear in mesh with saidv sun gear,Va :second planet gear in mesh with said first planet gear and with saidring gear, a third planet gear integrally connected With one of said rsttwo named planet gears, and a sun gear constituting a reaction gear andin -mesh with said third planet gear, clutch means for connecting saiddrive shaft with said iirst named sun gear to provide a power trainbetween said shafts at a reduced speed ratio, the initial movement ofsaid clutch means toward clutching engagement being hydraulicallyinstigated and the nal movement into clutching engagement beingresponsive to a predetermined speed of rotation of the drive shaft,hydraulically operated clutch means for connecting said drive shaft withsaid ring gear to provide a power train between said shafts at anintermediate speed ratio, land means for braking said reaction gear,

to provide a reaction point for the gear set to complete both of saidpower trains, said braking means comprising a one-way roller brake theinner race of which is `formed on a hub of said reaction sun gear andthe outer race of which has external teeth, a non-rotatable pawl adaptedto engage the teeth of said outer roller race to prevent rotationthereof and thereby render the one-way brake effective,a brake drumconnected with the hub of said reaction sun gear, and selectivelyoperable friction means for stopping the rotation of said drum and forthereby braking the reaction sun gear in both directions of rotation.

DONALD W. KELBEL.

